我什么都不是的回答：

disapproval: 不赞同 rejection: 拒绝 （这里一般指工作，例如项目 etc. 也可指爱情方面） refusal: 拒绝 （这里是人际关系之间） decline: 拒绝 (这里也是工作啦） so, someone may disapprove of you, but they may not do anything specifically. you're boss may reject your project or the university may reject you, but that does not mean you have no more chances. whilst if the person you like refused to go out with you, it is like saying "no is no" another company may decline your offer (at work) but you have the chance to improve your offer and aim another shot. 总之reject，refuse，decline几个个单词的意思很接近啦， 一般reject也可以是“撤回”然后refuse就是没有余地了，至于decline；一般在日常用语中很少用到啦。